The concentration of the plasticizer, di‐2‐ethylhexyl phthalate (DEHP), in the plasma was measured after storage of the whole blood in polyvinylchloride plastic bags at 4 C for up to 38 days in either ACD or CPD. The plasma from ACD‐stored whole blood contained more DEHP than that from CPD‐stored whole blood. The continuous‐flow centrifugation washing procedures removed about 98 per cent of the DEHP from ACD whole blood stored for 33 days at 4 C.DEHP was assayed in the platelet‐rich plasma, platelet‐poor plasma, supernatant of the platelet concentrate, washed platelets, and washed red blood cells prepared from CPD whole blood. Very little DEHP was found in the washed red blood cells and platelets, a small amount was found in the platelet‐poor plasma, and a large amount in the supernatant of the platelet concentrate. A greater amount of DEHP accumulated in the platelet concentrates that were stored at 22 C than in those stored at 4 C. When platelet concentrates from CPD whole blood were stored at 22 C for 72 hours, the amount of DEHP was about four times that observed after 4 C storage for the same